1. Field of the Invention
The present invention relates to a method of manufacturing a grounding construction for a plurality of shielded cables, such as a plurality of shielded cables arranged in an automotive vehicle. The invention also relates to a grounding construction for a plurality of shielded cables, and particularly to a grounding construction to join a plurality of shielded cables and to connect the shielded cables to a ground wire without using a joint connector.
2. Description of the Related Art
A prior art shielded cable includes one or more core wires disposed in a braided metal wire tube. The braided wire tube then is covered with a sheath or insulation coating. The braided wire is provided for shielding, and hence needs to be grounded. Thus, as shown in FIGS. 4(A) and 4(B), end portions of sheaths 1a of prior art shielded cables 1 are stripped to expose the braided wires, and the exposed braided wires are formed into drain twisted wires 1b. Terminals 2 are mounted at the leading ends of the twisted wires 1b and are inserted into a joint connector 3 for connection with a joint terminal 4 in the joint connector 3. A terminal at one end of a ground wire 5 is connected with the joint terminal 4, and a terminal 6 at the other end of the ground wire 5 is grounded to a vehicle body panel or the like.
The sheath 1a is stripped at a position P where the leading end of the prior art shielded cable 1 is branched, as shown in FIG. 5. For example, since the length of a branch wire 1-a is 100 mm in the shielded cable 1A, the length of a drain twisted wire 1b-1 is 100 mm. Further, since the length of a branch wire 1-b is 200 mm in a shielded cable 1B, the length of a drain twisted wire 1b-2 is 200 mm. Furthermore, since the length of a branch wire 1-c is 300 mm in a shielded cable 1C, the length of a drain twisted wire 1b-3 is 300 mm. The terminals 2 are mounted at the leading ends of the drain twisted wires 1b-1 to 1b-3 for connection with the joint terminal 4 in the joint connector 3. Tubes 7 are designed for insulation and protection, and are mounted on the twisted wires between the stripping positions P and connecting portions with the joint connector 3.
If the joint connector is used to ground the metal fiber braided wires of the plurality of shielded cables, as described above, a large space is taken up. However, there generally is not much space remaining in the arrangement of shielded cables. Accordingly, it often is difficult to ensure a mount space for the joint connector. Further, the use of the joint connector leads to an increased number of parts, such as a joint terminal, a joint connector, and tubes. The use of the joint connector also leads to an increased number of operation steps including the mounting of the terminals and the connection of the connector. This increase in the number of parts and the more complicated assembly disadvantageously increases costs.
If the ends of the drain twisted wires and the end of the ground wire are welded together, the joint connector is unnecessary. Thus, a spatial problem can be solved, the number of parts can be reduced, and the number of operation steps can be reduced. However, as shown in FIG. 6, the drain twisted wires differ in length. Furthermore, the drain twisted wires have a low rigidity and are difficult to straighten. Therefore, the leading ends cannot be aligned easily, and it is impossible to apply local welding thereto at the present state.
In view of the above problems, an object of the present invention is to enable ends of drain wires of a plurality of shielded cables and an end of a ground wire to be locally end-processed, in particular connected or welded together, so that a joint connector can be dispensed with.